How much sunlight do bifacial solar panels need to produce energy?

Bifacial solar panels produce energy using both direct sunlight and reflected light, making them effective even in cloudy UK conditions. While direct sunlight increases output, they don’t require constant, intense sun and can harness diffuse light common in British weather.

Key factors affecting energy production

Light requirements and UK conditions

• Direct vs. indirect sunlight: Bifacial panels capture light from both sides, using reflected sunlight from surfaces like snow, light-coloured walls, or gravel.
• Diffuse light advantage: They perform better than traditional panels on overcast days due to their dual-sided design, which captures scattered light.
• Reflective surfaces: Installing near light-coloured roofing, swimming pools, or vertically on flat commercial roofs (common in UK cities) can boost output by 10–30%, depending on reflectivity.

Real-world UK applications

• Home installations: Mounted on pergolas or south-facing rooftops with light-coloured surfaces beneath.
• Commercial setups: Vertically installed on flat-roofed warehouses or industrial buildings (e.g., in London or Manchester) to capture low-angle sunlight.
• Cost vs. benefit: While 10% more expensive than traditional panels (£9,900–£11,000 for homes), bifacial systems often generate more energy per square metre, ideal for space-constrained properties.

Practical advice for UK owners

• Optimal placement: Angle panels to capture morning/evening sun and elevate them to maximise ground-reflected light.
• Avoid common mistakes:
• Positioning near dark asphalt or dense vegetation, which reduces reflectivity.
• Ignoring tilt angles – use adjustable mounts to adapt to seasonal sun paths.
• Maintenance: Clean panels regularly, as UK rain often leaves dust or pollen that blocks light absorption.

Pros and cons

• Pros:
• Higher efficiency (up to 30% more output in ideal conditions).
• Better performance in cloudy weather compared to monofacial panels.
• Cons:
• Higher upfront cost.
• Requires careful installation to exploit reflective surfaces.

Recent UK trends: Developers increasingly use bifacial panels in urban solar farms and commercial retrofits due to 2023–2025 policy incentives for efficient renewable systems.